US banks are making a last-minute push to ease new global liquidity requirements, arguing that they would need to come up with an additional $800bn in easy to sell assets under the proposed standards.

The banks argue that they have increased their holdings of liquid assets by $700bn – or about half the $1.5tn shortfall identified in the US at the end of 2010. Rather than raising the difference, they want the new Basel III bank safety rules to be relaxed.

“The US banking industry is significantly more liquid than it was even just two years ago,” said Bob Chakravorti, chief economist at the Clearing House, which represents the 11 largest US commercial banks. “With certain recalibrations to the proposed Basel III requirement that are more reflective of market conditions, the industry would meet the proposed liquidity requirement and be well positioned to withstand a future financial shock.”